The present invention relates to a sorting device for flat items of mail, having at least one input station, in each case having a mail separating device and a following transport device for transporting the separated items of mail past process appliances, such as readers, bar code printers, to a loading station of a mail buffer store in each case, the mail buffer store comprising a plurality of storage pockets which circulate in a conveying loop and are moved past the loading stations, and which are loaded with the mail in the loading stations.
In order to sort flat items of mail, such as letters, postcards, small packets and the like in accordance with the, distribution information specified on the surface, it is known to accommodate these items of mail, to transport them and to discharge them in a controlled manner in specific pocket-like containers.
For example, EP 0 608 161 A1 discloses a salting device in which flat objects are transported laterally into storage pockets from outside by means of a channel-like, locally fixed feed device. These storage pockets, circulating in a closed loop, are moved horizontally past the feed device and the items of mail then fall into sorting containers located underneath by means of specific opening of flaps accordance with the sorting stipulation. In order to put the items of mail securely into the moving storage pockets, either the items of mail in the feed device must have a very high transport speed, which can lead to damage when braking the items of mail in the container, or the speed of the storage pockets is very low or the containers are at a standstill during the input, which means a reduction in the throughput of the machine.
For the purpose of ordering in a specific sequence, and solution has been disclosed (EP 820 818 A1) which uses an intermediate store, which comprises storage pockets circulating on a conveyor device in a conveyor loop having at least two semicircular conveyor sections, it being possible for said storage pockets each to pick up an item of mail and to deposit is in the actual tray again when instructed. In this case, initially all the items of mail to be ordered are accommodated in any desired sequence in the storage pockets of the intermediate store. The items of mail are then removed from the storage pockets of the intermediate store and transferred into the trays in such a way that they are located in the latter in the order to be produced. The trays, which are open at the top, are located along the straight sections of the conveyor device, underneath the storage pockets.
In order to improve the input of the items of mail into the storage pockets, according to WO 97/10904 the end section of the transport means of the feed device is designed such that it can be pivoted so that, doing the input of the respective item of mail, this end section is pivoted together with the moved storage pockets in substantially the same direction and at substantially the same speed and, following the input, is pivoted back again.
The throughput of these sorting devices is limited by the throughput of the circulating storage pockets. An increase in the throughput can theoretically be achieved only by increasing the speed and/or reducing the pitch of the transport system of the storage pockets. However, as outlined (input into the storage pockets), this is possible only to a very limited extent.
A sorting device (EP 0 949 015 A2) has also been disclosed which has a plurality of input units, at least one mail buffer store with continuously circulating storage pockets, mail containers as final sorting points, which are filled from the different mail, buffer stores, and with an input and output device for mail containers. In this case, it is possible to manage with fewer final sorting points than there are sorting destinations.